Question

Which of the following reaction is correct?

• A. $2 LiNO _3 \xrightarrow{\Delta} 2 NaNO _2+ O _2$
• B. $4 LiNO _3 \xrightarrow{\Delta} 2 Li _2 O +2 N _2 O _4+ O _2$
• C. $2 LiNO _3 \longrightarrow 2 Li +2 NO _2+ O _2$
• D. $4 LiNO _3 \xrightarrow{\Delta} 2 Li _2 O +4 NO _2+ O _2$

Answer 1

The Correct Option is D

In this question, we are given a set of chemical reactions, and we need to identify the correct decomposition reaction of lithium nitrate \((LiNO_3)\). Let's evaluate each option to determine the correct one.

1. \(2 LiNO_3 \xrightarrow{\Delta} 2 NaNO_2 + O_2\) 
   This reaction suggests that lithium nitrate decomposes to form sodium nitrite, which is chemically incorrect because sodium \((Na)\) cannot be formed from lithium \((Li)\) in a thermal decomposition reaction.
2. \(4 LiNO_3 \xrightarrow{\Delta} 2 Li_2O + 2 N_2O_4 + O_2\) 
   This reaction implies the production of \((N_2O_4)\) and does not balance with the typical decomposition products of lithium nitrate.
3. \(2 LiNO_3 \longrightarrow 2 Li + 2 NO_2 + O_2\) 
   This incorrectly suggests that pure lithium metal is formed from lithium nitrate, which does not occur in typical decomposition reactions under heating.
4. \(4 LiNO_3 \xrightarrow{\Delta} 2 Li_2O + 4 NO_2 + O_2\) 
   This reaction is correct because it appropriately represents the thermal decomposition of lithium nitrate. The balanced chemical equation shows lithium nitrate decomposing into lithium oxide \((Li_2O)\), nitrogen dioxide \((NO_2)\), and oxygen \((O_2)\).

Therefore, the correct reaction is:

\(4 LiNO_3 \xrightarrow{\Delta} 2 Li_2O + 4 NO_2 + O_2\)

Reasoning: On heating, lithium nitrate decomposes to give lithium oxide, nitrogen dioxide, and oxygen. This follows the general decomposition pattern for alkali metal nitrates, which typically produce metal oxides, nitrogen dioxide, and oxygen.